Artificial tooth-crown



(No Model.)

D. GENESE.

ARTIFICIAL TOOTH GROWN. 7 No. 430,522. Patented June 17, 1890.

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NITED STATES PATENT OFF CE.

DAVID GENESE, OF BALTIMORE, MARYLAND.

ARTIFICIAL TOOTH-CROWN.

SPECIFICATION forming part of Letters Patent No. 430,522, dated June 17,1890 Application filed November 13, 1889- Serial No. 330,214. (Nomodel.)

To all whom it may concern."

Be itlcnown that I, DAVID GENEsn, a citizen of the United States,residing at Baltimore, in the State of Maryland, have invented new anduseful Improvements in the Art of Attaching Artificial Crowns to NaturalRoots, of which the following is a specification.

This invention relates to pivot-teeth wherein an artificial crown isconnected with a natural root by a pin or post.

The object of my invention is to provide a crown having a peculiarinternal construction to which the post can be fitted, adjusted, andsoldered at any angle that may-be required by the nature or formation ofthe rootcavity and the pulp-canal.

The invention also has forits object to provide a novel post forattaching artificial crowns to roots, whereby the post is steadied by acollar resting against the inside of the walls of the root-cavity, andof such construe tion that the cement employed can pass by the collarinto the root and crown.

The invention also has for its object to provide a post with a collarthat can be adjusted to different positions thereupon and then besoldered in the desired position, as conditions of the natural root mayrequire, so that the collar bears against the inner surface of theroot-cavity and steadies the post to prevent rocking thereof andmateriallystrengthen the pivot-connection of the artificial crown withthe root. 1

The invention also has for its object to provide a novel and simpleconstruction of parts whereby the post can be fitted to the root and tothe crown before permanently fixing one part to the other.

To accomplish these objects my invention involves the peculiar featuresof construction, the combination or arrangement of parts, and theprinciples of operation hereinafter described, and specifically setforth in the claims, reference, being made to the accompanying drawings,in which Figure 1 is an enlarged sectional view of the crown with thepost in side elevation, showing by dotted lines different positions towhich the post can be adjusted and then soldered; Fig. 2, a similar viewshowing a modified construction of post; Fig. 3, an enlarged sectionalview of a natural root with the post and crown in position; Fig. 4, aside view showing the post provided with an adjustable annularsteadying-collar, and Figs. 5 and (5 enlarged side views of other poststo be used in connection with the peculiarcrown shown.

In order to enable those skilled in the art to make and use myinvention, I will now describe the same in detail, referring to thedrawings, wherein The numeral 1 indicates an artificial toothcrowncomprising a shell in which the cavity is bounded by a flattened bottomwall 2 and side walls 3, continuously lined with platina, as at 4, whichmaterial I employ, so that a pivot-post can be soldered to it after suchcrown is fitted by grinding to the natural root. The platina lining isground away with the porcelain crown in fitting the latter, and theplatina lining serves not only to permit soldering the pivot in place,but also to prevent the cement which is employed to fix the post in thecrown from discoloring the latter, and, further, to relieve the crownitself from strain of the pin and to strengthen the side and flat bottomwalls of the crown. The construction of the crown with the fiat orflattened bottom to its bowl-like chamber is necessary to permit apivot-post to be adjusted to different positions, as indicated by dottedlines, Fig. 1, as may be required to fit the crown to a natural root,wherein the pulp or nerve canal runs at an inclination to aperpendicular.

The pivot pin or post 5 is tapering to form an enlarged head 6 andconform, as nearly as possible, with the pulp or nerve canal of the rootof a natural tooth. The collar 12 is annular, and is adapted to restagainst the inner surface of the wall 7 of the decayed cavity 8 of anatural root 9, while that part of the pin above the collar enters thepulp-canal 10 in such manner that the pin or post is steadied, braced,and prevented from rocking. This construction is important, for if thepin simply entered the pulp-canal and there existed a decayed cavity orother enlarged hollow at the base of the cone-root there would be nosupport for that portion of the pin or post beyond the usual cement usedto hold the pin in the root. In consequence of this the pin Connectionis weak, the pin rocks, and the crown becomes loose. By my constructionthe annular collar does not seat against the base of the cone-root toserve as an abutment for the crown, as has heretofore been proposed; butthe collar is especially for the purpose of setting up within arootcavity to bear against the internal surface of the walls of theroot, thereby forming a stay piece which braces the post against lateralmovement in any direction, while the post itself can be made very narrowin diameter to enter and seat in the pulp-canal of the natural root.

The collar can be moved along the length of the post to vary itsdistance from the apex of the cone-root, as in Fig. 4, in order to adaptthe post and collar to the conditions required by the depth or size ofthe decayed or other hollow and enlarged part of the base of the root,and after the correct position is ob tained the collaris soldered to thepost. The collar that I prefer is one of dish form or made concavoconvex, formed with radial slots or otherwise provided with openings 13to permit the cement to flow or pass by the collar when the post isinserted into the root and forced into position, so that the cement willcompletely fill the root-cavity and crown.

By my peculiar construction of crown with its bowl-like cavity boundedby the flat bottom wall and continuously lined witha sheet of platinapressed thereinto I am enabled to grind the crown and upper edge of thelining to accurately fit the base of the root and then solder the postinto the crown against the flat bottom wall, with ample spacesurrounding the post and between the latter and the side wall of thecrown for the cement. In practice I first grind the crown to accuratelyfit the root and fit the post and collar to the root. I then place waxin the crown and press it on the end of the post which projects from theroot, whereby the correct relative position of the root, post, and crownis obtained. I then withdraw the crown with the post therein, and bythen soldering the post in place it is in proper relative position to becemented in the root, thereby insuring a perfect joint with nopossibility of displacement and without unsightly gold bands being visible at the necks of the teeth.

' By my peculiar crown lined with platina a dentist can with a shortpost replace a broken crown on the root that retains the pivot-pin ofthe broken crown without disturbing the cement, thus avoiding thepossibility of infiammation,which is so common where the old brokenpivot is disturbed.

As regards the adjustment of the collar and the setting of the post atdifferent inclinations in the crown, the annular collar may or may notbe perforated. The purpose of the collar is to rest uniformly againstthe internal surface of the root-cavity at a point above the base of theroot to form a continuous stay-piece entirely around the post to preventlateral movement of the post in one direction, and this in connectionwith the formation of the peculiar fiat-bottomed cavity and platinalining of the bowl give awide range of adjustment for the pivot withoutbending any part of the post.

The shape of the platina lining in my construction permits the post tostand at any angle and still be made fiat on its lower end for solderingto the flat wall of the crown, while providing a surrounding spacebetween the lower end portion of the post and the side walls of theplatina lining and crown for the proper reception of the cement.

In Figs. 5 and G I show tubular or hollow posts, which are perforated ormade foraminous, so that the cement can form or pass into the crown whenthe post is forced into the cement. in the root. The post shown in Fig.5 can be made from a very thin piece of metalsuch as gold cut to atriangular form and rolled on a tapering pivot or mandrel. This flexiblepost easily enters a root, and by rotating a suitable instrumentinsidethe hollow post the latter can be pressed toward the walls of the root,and thereby caused to accurately fit the cavity. It is then soldered tothe platina lining of the crown, and when pressed into the cement in theroot the perforations permit the cement to pass from the root into thecrown, so that the root and crown are correctly filled with the cement.The post shown in Fig. 6 is composed of perforated plate or piece ofvery small gage wire-gauze made of gold or pure platina. It ispreferably tapering, but not necessarily so, and it can be applied andmanipulated, as described, with' reference to the post shown in Fig. 5,or otherwise.

The requisite strength is given to the posts described by the solderingprocess, and by this part of my invention frail roots are not subjectedto the strain incident to a solid pivot, while irregularities in theroot-cavity or pulp-canal are met without strain.

The post having some part perforated, as in Fig. 1 or Figs. 5 and 6, canbe correctly applied without danger of working loose from continuedfriction, this result being attained by providing for the flow orpassage of the cement, as hereinbefore explained.

Having thus described my invention, what I claimis- 1. Theartificialcrown described herein,having a bowl-shaped cavity 'lined withplatina, in combination with a post having its end soldered to saidplatina lining, substantially as described.

2. The herein described artificial toothcrown, having a bowl-like cavitybounded by a flattened bottom wall and side walls and continuously linedwith platina, as and for the purposes set forth.

3. The artificial crown herein described,ha"- ing a bowl-shaped cavitybounded by a flatened bottom and side walls, and having a conthe postfor entering and bearing against the inside of a root-cavity,substantially as described. I

6. A tooth-crown post, a part of which is provided with perforations toperniit the ce1n ent to pass therethrough from a natural root to anartificial crown substantially as described.

In testimony whereof I have affixed my Sig nature in presence of twowitnesses.

DAVID GENESE. \Vitnesscs:

G. EVERETT REARDON, J. EDWARD BENNETT.

